The invention relates to a mechanical pull type control mechanism for a load to be jettisoned or dropped from a vehicle, inter alia an aircraft, comprising a flexible cord or lanyard, one end of which is adapted to be connected to the vehicle via a pull-away connection and the other end of which is connected to the load.
Mechanisms of this kind are widely used in civil and military aviation, for instance, to pull out a parachute, light a jet motor or thruster, launch a rotating generator which will subsequently be wind-driven or activate a firing fuse. The mechanism must activate the load only when the same has moved far enough away from the vehicle to meet a safety or guard condition or to remove any risk of aerodynamic interaction between the carrying vehicle and the load it has jettisoned.
It is an object of the invention to provide an improved control mechanism, which is simple and economical in construction, reliable in operation and readily adaptable to a very wide variety of loads.
According to an aspect of the invention, there is provided a mechanical pull type control mechanism for a load jettisonable from a vehicle comprising a flexible cord, one end of which is constructed to be secured to the vehicle via a pull-away connection and the other end of which is constructed to be connected to the load, and a sheath constructed to be secured to the load and having a number of channels slidably locating consecutive loops of the flexible cord.
According to a particular embodiment of the invention, the sheath (which can be flexible or rigid) is carried on a support, such as a strap or sleeve, adapted to be secured to the load, for instance by encircling it in the most appropriate position. The sheath, particularly if rigid, can as well be secured to the load directly, e.g. by means of screws screwed into threaded holes. A number of such holes can be distributed along the load to give a choice of places where the sheath can be secured. The resulting flexibility in use is far better than can be provided by a control mechanism which is integral with the load and therefore in a fixed position which cannot be altered.